Pope Francis gave mass at Revolution Square in Havana, Sunday Sept. 20. Francis greeted massive crowds of fans and Catholic faithful Sunday as he arrived in his popemobile to give mass on Havana's iconic Revolution Square, the highlight of his trip to Cuba. The pontiff's eight-day tour will also take him to the United States. Photo: AFP/Getty Images

UPDATE 11:45 a.m. EDT:

A crowd of 300,000 people attended mass in Revolutionary Square in Havana, Cuba, Sunday, Vatican officials reported. Large crowds gathered outside to partake in the morning Mass.

Pope Francis has been met with some protest but largely great enthusiasm since arriving for his historic visit to Cuba beginning Saturday. Police tackled an apparent protester in Revolutionary Square in Havana Sunday morning ahead of Francis' scheduled Mass at the famed monument. Police have not yet released any information on the man who was detained and no other incidents have been reported. The tour of Cuba is the pontiff's first visit since the beginning of his papacy in 2013.

While the pope's presence has been controversial in a number of circles, many Cubans are embracing the visit. Residents posted signs throughout the capital welcoming the pope, and several stands throughout Havana were selling pope souvenirs, including Cuban flags with the pope's face and signs bearing the pope's likeness to wave upon his arrival. One seller was even hawking pope calendars, signaling the pope's arrival as the start of a new year, the Daily Beast reported.

Several thousand people were expected to attend Pope Francis' Sunday Mass. Social media posts showed large crowds gathered in the square hours before the service was set to begin.

After Sunday Mass in Havana, the pope has a scheduled meeting with Cuban President Raul Castro. The pope's visit to Cuba has faced criticism, particularly from human rights activists who point to the high proportion of political prisoners in Cuba as well as other human rights violations. Opponents of the trip urged the pope to address these concerns during his time there.

From Havana, Francis was set to fly to the city of Holguín, in eastern Cuba Monday, followed by a trip to Santiago in the southern part of the island Monday afternoon for further Masses and blessings in the cities. Tuesday morning the pope is scheduled to fly to Washington D.C. for the beginning of his U.S. tour.